I’m not convinced running your own service is cheaper than paid solutions in general, if Slack can provide the same service for cheaper than it should be considered even if it’s no longer free.

I also don’t see it as a moral failing for a company to cripple/take away it’s free offerings unless it promised/guaranteed otherwise (like Google did with the Workplace Apps).

However I do see a major issue with Slack’s pricing structure - the per user pricing means it’s a lot more suited for communities or companies with small number of highly engaged users than large number of low engagement users, the latter end up costing a LOT more for the same server load, which seems like a major missed opportunity.

Unless of course Slack determines that they could earn more by doing it this way, even with the number of potential customers they’re losing.